Mucormycosis outbreak associated with hospital linens

How long do bacteria, fungi, protozoa, and viruses retain their replication capacity on inanimate surfaces? A systematic review examining environmental resilience versus healthcare-associated infection risk by "fomite-borne risk assessment"

SUMMARYIn healthcare settings, contaminated surfaces play an important role in the transmission of nosocomial pathogens potentially resulting in healthcare-associated infections (HAI). Pathogens can be transmitted directly from frequent hand-touch surfaces close to patients or indirectly by staff and visitors. HAI risk depends on exposure, extent of contamination, infectious dose (ID), virulence, hygiene practices, and patient vulnerability. This review attempts to close a gap in previous reviews on persistence/tenacity by only including articles (n = 171) providing quantitative data on re-cultivable pathogens from fomites for a better translation into clinical settings. We have therefore introduced the new term "replication capacity" (RC). The RC is affected by the degree of contamination, surface material, temperature, relative humidity, protein load, organic soil, UV-light (sunlight) exposure, and pH value. In general, investigations into surface RC are mainly performed in vitro using reference strains with high inocula. In vitro data from studies on 14 Gram-positive, 26 Gram-negative bacteria, 18 fungi, 4 protozoa, and 37 viruses. It should be regarded as a worst-case scenario indicating the upper bounds of risks when using such data for clinical decision-making. Information on RC after surface contamination could be seen as an opportunity to choose the most appropriate infection prevention and control (IPC) strategies. To help with decision-making, pathogens characterized by an increased nosocomial risk for transmission from inanimate surfaces ("fomite-borne") are presented and discussed in this systematic review. Thus, the review offers a theoretical basis to support local risk assessments and IPC recommendations.

An Update on Fungal Disease Outbreaks of Public Health Concern

For this narrative review, we describe recent high-profile and severe outbreaks of emerging fungal infections, emphasizing lessons learned and opportunities to improve future prevention and response efforts. Several themes and challenges remain consistent across a diverse array of fungal outbreaks, including the multidisciplinary need for improved diagnostic testing to determine species and perform antifungal susceptibility testing, clinical awareness, and optimization of antifungal use. Recent outbreaks exemplify the growing promise of non-culture-based tools in identifying fungal outbreaks and improving responses, although access remains limited. Culture-based tools remain critical for performing antifungal-susceptibility to guide therapy.

S, V. SD, Duvvur NR. An Experience in Laboratory Diagnosis of Fungal Infections in COVID -19 Patients

Introduction  Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has cast a gloom spell on healthcare worldwide, infecting millions of people. Objective  The aim of the present study is to determine the prevalence and review the contributing comorbidities and the precipitating factors leading to the emergence of the fungal infections in COVID-19-affected patients. To assess the utility of different laboratory techniques for confirmation of fungal infections. To assess the strengths and limitations of the diagnostic methods. Methods  We have studied 252 clinical samples obtained from 121 COVID-positive patients. Results  Among the 121 patients clinically diagnosed with fungal infections, 88 had diabetes and were given steroids for treatment ( p -value = 0.001). Ninety-five patients (78.5%) had a positive laboratory diagnosis (either culture positive, potassium hydroxide [KOH]-positive or positive histopathology report). Fungal culture was positive in 75 (61.9%) patients and histopathology report was positive in 62 (51.2%). Histopathology was positive in 7 (5.8%) patients in whom culture and KOH were negative. Conclusion  Aggressive treatment methods, administration of immune suppressants, and antibiotics, with an intention to salvage, have made patients susceptible to the benign fungus, causing it to evade the host immunity, thus leading to invasive infections. Applying different laboratory modalities would not only aid in providing fast and valuable information but also help in understanding the pathology which would assist the clinician in selecting the correct treatment for the patient.

Clinical, Demographic, and Oral Presentations of COVID-19 Associated Mucormycosis from a Tertiary Care Hospital in India: A Cross-Sectional Study

Background

The black fungus, mucormycosis, is on the list of lethal complications reported in recent times in COVID patients.

Methodology

This cross-sectional study included all cases of post-COVID-19 mucormycosis. Patients' demographics, clinical presentations, and general health information were collected using a pre-designed form.

Results

The study included 171 participants with the mean (SD) age as 49 (10) years with the sex distribution as 71% (122/171) male and 29% (49/122) females. About half of the admitted patients (47%) were known cases of Diabetes Mellitus type II with a median (IQR) Glycosylated Haemoglobin (HbA1c) of 9.1% (7-11.1%). Only 28% (48/171) had received the first COVID vaccination, and 2.9% (5/171) were fully vaccinated with two doses. During COVID-19, 76% (130/171) required hospitalisation for a mean (SD) stay of 11 (6.4) days. Eighty percent of the patients (136/171) received steroids during therapy, while 87% (150/171) and 51% (88/171) received antibiotics and antivirals, respectively. Oxygen was administered to 71% of hospitalised patients (120/171), with 39.1% (47/120) receiving it for more than 7 days. About the development of the first symptoms of mucormycosis (headache, nasal congestion, black crusts in the nose, facial pain, swelling in cheeks and eyes, and loss of vision) after being diagnosed with COVID-19, 16% (28/171) reported it within 7 days, 75% (127/171) between 8 and 30th days and 9% (16/171) after a month. On examination, 20% of mucor patients had hard palate findings, eschars, fistulas, and perforations, 38% had periodontal abscesses, and 5% reported tenderness to percussion.

Conclusion

Generally, oral manifestations involved the palate and included varying degrees of mucosal discolouration, swelling, ulcers, superficial necrotic areas, and bone exposure and necrosis with dark eschars.

Outbreaks of Fungal Infections in Hospitals: Epidemiology, Detection, and Management

Nosocomial clusters of fungal infections, whilst uncommon, cannot be predicted and are associated with significant morbidity and mortality. Here, we review reports of nosocomial outbreaks of invasive fungal disease to glean insight into their epidemiology, risks for infection, methods employed in outbreak detection including genomic testing to confirm the outbreak, and approaches to clinical and infection control management. Both yeasts and filamentous fungi cause outbreaks, with each having general and specific risks. The early detection and confirmation of the outbreak are essential for diagnosis, treatment of affected patients, and termination of the outbreak. Environmental sampling, including the air in mould outbreaks, for the pathogen may be indicated. The genetic analysis of epidemiologically linked isolates is strongly recommended through a sufficiently discriminatory approach such as whole genome sequencing or a method that is acceptably discriminatory for that pathogen. An analysis of both linked isolates and epidemiologically unrelated strains is required to enable genetic similarity comparisons. The management of the outbreak encompasses input from a multi-disciplinary team with epidemiological investigation and infection control measures, including screening for additional cases, patient cohorting, and strict hygiene and cleaning procedures. Automated methods for fungal infection surveillance would greatly aid earlier outbreak detection and should be a focus of research.

Environmental monitoring for filamentous fungal pathogens in hematopoietic cell transplant units

The incidence of invasive fungal disease (IFD) is on the rise due to increasing numbers of highly immunocompromized patients. Nosocomial IFD remains common despite our better understanding of its risk factors and pathophysiology. High-efficiency particulate air filtration with or without laminar air flow, frequent air exchanges, a positive pressure care environment, and environmental hygiene, amongst other measures, have been shown to reduce the mould burden in the patient environment. Environmental monitoring for moulds in areas where high-risk patients are cared for, such as hematopoietic cell transplant units, has been considered an adjunct to other routine environmental precautions. As a collaborative effort between authors affiliated to the Infection Prevention and Control Working Group and the Fungal Infection Working Group of the International Society of Antimicrobial Chemotherapy (ISAC), we reviewed the English language literature and international guidance to describe the evidence behind the need for environmental monitoring for filamentous fungi as a quality assurance approach with an emphasis on required additional precautions during periods of construction. Many different clinical sampling approaches have been described for air, water, and surface sampling with significant variation in laboratory methodologies between reports. Importantly, there are no agreed-upon thresholds that correlate with an increase in the clinical risk of mould infections. We highlight important areas for future research to assure a safe environment for highly immunocompromized patients.

Maxillary defects due to COVID-19 associated mucormycosis: Impact on quality of life after rehabilitation with an obturator

STATEMENT OF PROBLEM

Aggressive surgical debridement including maxillectomy in patients with coronavirus disease 2019 (COVID-19) associated mucormycosis of the maxilla alters facial appearance, function, and an individual's overall quality of life (QOL). These patients require rehabilitation of defects with obturators to help them recover from esthetic and functional disabilities and regain near-normal quality of life. Because COVID-19 associated with mucormycosis is a newer entity, less is known about the quality of life of these patients after rehabilitation with obturators. Hence, the effects of COVID-19 associated with mucormycosis, treatment, and rehabilitation need to be evaluated to assess QOL.

PURPOSE

The purpose of this clinical study was to assess the impact on QOL after rehabilitation with obturators for participants with COVID-19-associated mucormycosis who underwent maxillectomy.

MATERIAL AND METHODS

Oral health impact profile-14 (OHIP-14) and obturator functioning scale (OFS) questionnaires were administered to 26 participants with COVID-19-associated mucormycosis of the maxilla who underwent maxillectomy and required rehabilitation with obturators. Questionnaire responses were received on numerical Likert scales of 0 to 4 for OHIP-14 and 1 to 5 for OFS. The repeated measures analysis of variance (ANOVA) with pairwise post hoc Bonferroni tests were used to evaluate and compare mean scores of OHIP-14 and OFS at different preoperative and postoperative stages (α=.05).

RESULTS

A total of 26 participants who underwent maxillectomy were provided with obturators. A higher mean ±standard deviation OHIP score was observed before rehabilitation at T1 (51.0 ±9.6) followed by 1 week after fabrication of the surgical obturator at T2 (18.6 ±16.4), and 1 week after fabrication of the interim obturator at T3 (4.7 ±8.2). The lower mean scores ±standard deviation were seen 1 week after the fabrication of definitive obturators at T4 (2.9 ±7.2). Comparison of the scores at T1, T2, T3, and T4 found significant difference (P≤.001). Similarly, higher mean ±standard deviation OFS scores were seen 1 week after rehabilitation with surgical obturators at T2 (27.3 ±12.6) and at least 1 week after fabrication with definitive obturators at T4 (15.7 ±5.6). A comparison of the scores at T2, T3, and T4 found significant differences (P≤.001).

CONCLUSIONS

Considerable improvement was seen in QOL with the fabrication of surgical obturators in participants who had received maxillectomy/debridement for mucormycosis. This improvement had a linear relationship with the time elapsed and the consecutive fitting of the obturators with healing.

Epidemiology, Modern Diagnostics, and the Management of Mucorales Infections

Mucormycosis is an uncommon, yet deadly invasive fungal infection caused by the Mucorales moulds. These pathogens are a WHO-assigned high-priority pathogen group, as mucormycosis incidence is increasing, and there is unacceptably high mortality with current antifungal therapies. Current diagnostic methods have inadequate sensitivity and specificity and may have issues with accessibility or turnaround time. Patients with diabetes mellitus and immune compromise are predisposed to infection with these environmental fungi, but COVID-19 has established itself as a new risk factor. Mucorales also cause healthcare-associated outbreaks, and clusters associated with natural disasters have also been identified. Robust epidemiological surveillance into burden of disease, at-risk populations, and emerging pathogens is required. Emerging serological and molecular techniques may offer a faster route to diagnosis, while newly developed antifungal agents show promise in preliminary studies. Equitable access to these emerging diagnostic techniques and antifungal therapies will be key in identifying and treating mucormycosis, as delayed initiation of therapy is associated with higher mortality.

Biosynthesis, Characterization, and Antifungal Activity of Novel Trimetallic Copper Oxide-Selenium-Zinc Oxide Nanoparticles against Some Mucorales Fungi

Metal nanoparticles are assumed to be a new generation of biologically active materials. The integrations between more than one metal are synergetic multifunctional features. In the current study, trimetallic copper-selenium-zinc oxide nanoparticles (Tri-CSZ NPs) were successfully mycosynthesized using Aspergillus niger through an ecofriendly method for the first time. The biosynthesis of the particles was characterized using physiochemical and topographical analysis. The physiochemical analysis included Fourier transform infrared spectroscopy (FTIR), which affirmed that the biosynthesis of Tri-CSZ NPs relies on the functional groups of fungal filtrates. Additionally, the UV-visible and X-ray diffraction patterns were proposed for the formation of Tri-CSZ NPs; moreover, topography analysis confirmed that the micromorphology of the nanoparticles were similar to a stick, with ends having a tetragonal pyramid shape, and with an average nanosize of about 26.3 ± 5.4 nm. Cytotoxicity results reveled that the Tri-CSZ NPs have no cytotoxicity on the human normal cell line Wi 38 at low concentrations, where the IC50 was 521 µg/mL. Furthermore, the antifungal activity of the Tri-CSZ NPs was evaluated. The antifungal results revealed that the Tri-CSZ NPs have promising antifungal activity against Mucor racemosus, Rhizopus microsporus, Lichtheimia corymbifera, and Syncephalastrum racemosum, where the minimum inhibitory concentrations (MICs) were 1.95, 7.81, 62.5, and 3.9 µg/mL, and the minimum fungicidal concentrations (MFCs) were 250, 62.5, 125, and 1000 µg/mL, respectively. In conclusion, Tri-CSZ NPs were successfully mycosynthesized using A. niger, which have a promising antifungal activity against fungi causing mucormycosis.

Black fungus outbreak in India - A direct consequence of COVID-19 surge: A myth or reality

The deadly second wave of COVID-19 has seen an unprecedented surge in mucormycosis associated mortality in India, overwhelming the heath authorities with challenges beyond measure. Also known as black fungus, this life-threatening fungal infection usually manifests in the nose, spreads to the eyes, and in some cases also to the brain. Immune suppression, pre-existing conditions, prolonged and indiscriminate use of steroids, and unhygienic environments are some of the widely recognized risk factors for contracting black fungus in individuals recovered from COVID-19. However, diagnosis of the infection remains insufficient due to the lack a holistic understanding of the possible risks, symptoms, and exposure pathways and therefore no definite protocol exists for managing this fatal infection. Here, we synthesize the current state of knowledge on black fungus outbreak in India and identify key gaps in its understanding with respect to potential risk factors leading to the widespread infection. We looked at 3354 black fungus cases in India, enlisting ailment history (particularly diabetes) and steroid usage in COVID-19 patients as the key factors responsible for exacerbating risks associated with the disease. However, we also press on the possibilities that other less studied non-traditional risk factors may also have a role in causing the infection. Black fungus is therefore a reality of COVID-19, with or without diabetes or steroid use needs to be investigated. We believe such a review is imperative for making informed decisions specially around timely diagnosis and channelizing efforts in controlling the spread of COVID-19 associated mucormycosis.

Investigation of a Prolonged and Large Outbreak of Healthcare-Associated Mucormycosis Cases in an Acute Care Hospital-Arkansas, June 2019-May 2021

Background

Outbreaks of healthcare-associated mucormycosis (HCM), a life-threatening fungal infection, have been attributed to multiple sources, including contaminated healthcare linens. In 2020, staff at Hospital A in Arkansas alerted public health officials of a potential HCM outbreak.

Methods

We collected data on patients at Hospital A who had invasive mucormycosis during January 2017-June 2021 and calculated annual incidence of HCM (defined as mucormycosis diagnosed within ≥7 days after hospital admission). We performed targeted environmental assessments, including linen sampling at the hospital, to identify potential sources of infection.

Results

During the outbreak period (June 2019-June 2021), 16 patients had HCM; clinical features were similar between HCM patients and non-HCM patients. Hospital-wide HCM incidence (per 100 000 patient-days) increased from 0 in 2018 to 3 in 2019 and 6 in 2020. For the 16 HCM patients, the most common underlying medical conditions were hematologic malignancy (56%) and recent traumatic injury (38%); 38% of HCM patients died in-hospital. Healthcare-associated mucormycosis cases were not epidemiologically linked by common procedures, products, units, or rooms. At Hospital A and its contracted offsite laundry provider, suboptimal handling of laundered linens and inadequate environmental controls to prevent mucormycete contamination were observed. We detected Rhizopus on 9 (9%) of 98 linens sampled at the hospital, including on linens that had just arrived from the laundry facility.

Conclusions

We describe the largest, single-center, HCM outbreak reported to date. Our findings underscore the importance of hospital-based monitoring for HCM and increased attention to the safe handling of laundered linens.

Keeping health care linens clean: Underrecognized hazards and critical control points to avoid contamination of laundered health care textiles

Outbreaks of health care-associated infections, particularly invasive mold infections, have been linked to environmental contamination of laundered health care textiles. Contamination may occur at the laundry or health care facility. This report highlights underrecognized hazards, control points, and actions that infection preventionists can take to help decrease the potential for patient exposure to contaminated health care textiles. Infection preventionists can use the checklists included in this report to assess laundry and health care facility management of laundered health care textiles.

Linen: The New Frontier in Infection Control and Prevention

Personnel follow hospital policies and regulatory guidelines to prevent surgical site infections. However, a potentially contaminated item may be overlooked-the linen. When perioperative team members transport patients to the OR, the linen on the beds and transport carts can contain a variety of microorganisms. Textile surfaces can serve as reservoirs for microorganisms that can be transferred to health care providers, patients, and the environment. These pathogens may then infect patients, particularly those who are immunocompromised or have direct portals of entry (eg, catheters, incision sites). This article provides an overview of how microorganisms that cause health care-associated infections can survive and thrive on hospital linen and related equipment; discusses the linen laundering, transport, and storage processes and best practices; and discusses antimicrobial interventions-including a silver-ion laundering additive that was added as an infection prevention measure to the laundry production cycle at a medical center's contracted laundry facility.

Global Cutaneous Mucormycosis: A Systematic Review

Cutaneous mucormycosis is the third most common clinical type of mucormycosis. The signs and symptoms vary widely, and it is important to make the diagnosis as early as possible in order to achieve a better outcome. We present a systematic review of its epidemiology, clinical presentation, diagnosis, and treatment, analyzing cases published from 1958 until 2021. The review was conducted according to the PRISMA guidelines and included 693 cases from 485 articles from 46 countries. Most publications were from North America (256 cases, 36.9%) and Asia (216 cases, 31.2%). The most common risk factors were diabetes mellitus (20%) and hematological malignancies (15.7%). However, a large proportion of published cases (275, 39.6%) had no identified underlying disease. The most common mode of transmission was trauma (54%), and 108 (15.6%) cases were healthcare-associated. In this review, 291 (42.5%) patients had localized infection, and 90 (13%) had disseminated mucormycosis. In Europe, N. America and S. America, the most common genus was Rhizopus spp., while in Asia it was Apophysomyces spp. (34.7%). Treatment was performed with antifungals, mainly amphotericin B, and/or surgery. Mortality was significantly lower when both antifungals and surgery were applied (29.6%).

Mucormycosis (black fungus) ensuing COVID-19 and comorbidity meets - Magnifying global pandemic grieve and catastrophe begins

Post COVID-19, mucormycosis occurred after the SARS-CoV-2 has rampaged the human population and is a scorching problem among the pandemic globally, particularly among Asian countries. Invasive mucormycosis has been extensively reported from mild to severe COVID-19 survivors. The robust predisposing factor seems to be uncontrolled diabetes mellitus, comorbidity and immunosuppression acquired through steroid therapy. The prime susceptive reason for the increase of mucormycosis cases is elevated iron levels in the serum of the COVID survivors. A panoramic understanding of the infection has been elucidated based on clinical manifestation, genetic and non- genetic mechanisms of steroid drug administration, biochemical pathways and immune modulated receptor associations. This review lime-lights and addresses the "What", "Why", "How" and "When" about the COVID-19 associated mucormycosis (CAM) in a comprehensive manner with a pure intention to bring about awareness to the common public as the cases are inevitably and exponentially increasing in India and global countries as well. The article also unearthed the pathogenesis of mucormycosis and its association with the COVID-19 sequela, the plausible routes of entry, diagnosis and counter remedies to keep the infection at bay. Cohorts of case reports were analysed to spotlight the link between the pandemic COVID-19 and the nightmare-mucormycosis.

Mucormycosis Amid COVID-19 Crisis: Pathogenesis, Diagnosis, and Novel Treatment Strategies to Combat the Spread

The havoc unleashed by COVID-19 pandemic has paved way for secondary ominous fungal infections like Mucormycosis. It is caused by a class of opportunistic pathogens from the order Mucorales. Fatality rates due to this contagious infection are extremely high. Numerous clinical manifestations result in damage to multiple organs subject to the patient's underlying condition. Lack of a proper detection method and reliable treatment has made the management of this infection troublesome. Several reports studying the behavior pattern of Mucorales inside the host by modulation of its defense mechanisms have helped in understanding the pathogenesis of this angio-invasive infection. Many recent advances in diagnosis and treatment of this fungal infection have not been much beneficial. Therefore, there is a need to foster more viable strategies. This article summarizes current and imminent approaches that could aid effective management of these secondary infections in these times of global pandemic. It is foreseen that the development of newer antifungal drugs, antimicrobial peptides, and nanotechnology-based approaches for drug delivery would help combat this infection and curb its spread.

Primary cutaneous mucormycosis in a premature neonate treated conservatively with amphotericin B

Cutaneous mucormycosis is a rare, often fatal fungal infection that most commonly affects patients with underlying immunosuppression but also can occur in premature neonates. We report the case of an extremely premature boy (<25 weeks) who developed primary cutaneous mucormycosis shortly after birth. Although surgical debridement has been a mainstay of treatment in combination with antifungal therapy, our patient was successfully treated with amphotericin B alone-the management only reported in three other cases to date. We present this case to highlight that prompt initiation of treatment with amphotericin B alone may be an appropriate alternative to surgical intervention, particularly in patients with non-angioinvasive disease who are poor surgical candidates.

Invasive fungal infections in neonates: a review

Invasive fungal infections remain the leading causes of morbidity and mortality in neonates, especially preterm and very low birth weight infants. Most invasive fungal infections are due to Candida or Aspergillus species, and other fungi are increasingly reported and described. Appropriate identification and treatment are required to augment activity and reduce the toxicity of antifungal drugs. Successful use of antifungals in the vulnerable neonatal population is important for both prevention and treatment of infection. Strategies for prevention, including prophylactic antifungal therapy as well as reducing exposure to modifiable risk factors, like limiting antibiotic exposure, discontinuation of central catheters, and hand hygiene are key techniques to prevent and decrease rates of invasive fungal infections. In conclusion, this is a review of the most common causes, prevention strategies, prophylaxis, and treatment of invasive fungal infections in neonates.

Nosocomial Fungal Infections: Epidemiology, Infection Control, and Prevention

Invasive fungal infections are an important cause of morbidity and mortality in hospitalized patients and in the immunocompromised population. This article reviews the current epidemiology of nosocomial fungal infections in adult patients, with an emphasis on invasive candidiasis (IC) and invasive aspergillosis (IA). Included are descriptions of nosocomial infections caused by Candida auris, an emerging pathogen, and IC- and IA-associated with coronavirus disease 2019. The characteristics and availability of newer nonculture-based tests for identification of nosocomial fungal pathogens are discussed. Recently published recommendations and guidelines for the control and prevention of these nosocomial fungal infections are summarized.

Invasive Fungal Infections Among Immunocompromised Patients in Critical Care Settings: Infection Prevention Risk Mitigation

Most fungal infections are common in humans. Pathogenic fungi are opportunistic but can cause fungal infection disease in patients with immunocompromised conditions, such as malignancy, chemotherapy, transplantation, acquired immunodeficiency syndrome, and usage of immunosuppressant drugs. Most invasive infections are caused by Aspergillus species, mucormycetes, Cryptococcus species, and Candida species. This article focuses on environmental fungi such as Aspergillus species and mucormycetes because the mode of transmission is different. The purpose of this article is to discuss invasive fungal infections (IFIs) caused by environmental fungi and to educate critical care nurses about infection control and risk mitigation to prevent IFIs.

Opportunistic mycoses in COVID-19 patients/survivors: Epidemic inside a pandemic

Being considered minor vexations, fungal infections hinder the life of about 15% of the world population superficially, with rare threats to life in case of invasive sepsis. A significant rise in the intrusive mycoses due to machiavellian fungal species is observed over the years due to increased pathology and fatality in people battling life-threatening diseases. Individuals undergoing therapy with immune suppressive drugs plus recovering from viral infections have shown to develop fungal sepsis as secondary infections while recovering or after. Currently, the whole world is fighting against the fright of Coronavirus disease (COVID-19), and corticosteroids being the primitive therapeutic to combat the COVID-19 inflammation, leads to an immune-compromised state, thereby allowing the not so harmful fungi to violate the immune barrier and flourish in the host. A wide range of fungal co-infection is observed in the survivors and patients of COVID-19. Fungal species of Candida, Aspergillus and Mucorales, are burdening the lives of COVID-19 patients/survivors in the form of Yellow/Green, White and Black fungus. This is the first article of its kind to assemble note on fungal infections seen in the current human health scenario till date and provides a strong message to the clinicians, researchers and physicians around the world "non-pathological fungus should not be dismissed as contaminants, they can quell immunocompromised hosts".

Healthcare-associated Pediatric Cutaneous Mucormycosis at Texas Children's Hospital, 2012-2019

Cutaneous mucormycosis in children is an opportunistic fungal infection associated with significant morbidity and mortality. We describe characteristics of 12 patients with healthcare-associated cutaneous mucormycosis at Texas Children's Hospital and results of an outbreak investigation. A definitive source was not identified. Skin lesions near medical device securement sites should raise concern for mucormycosis in patients with underlying medical conditions.

Remediation of Mucorales-contaminated Healthcare Linens at a Laundry Facility Following an Investigation of a Case Cluster of Hospital-acquired Mucormycosis

BACKGROUND

In an investigation of hospital-acquired mucormycosis cases among transplant recipients, healthcare linens (HCLs) delivered to our center were found to be contaminated with Mucorales. We describe an investigation and remediation of Mucorales contamination at the laundry supplying our center.

METHODS

We performed monthly RODAC cultures of HCLs upon hospital arrival, and conducted site inspections and surveillance cultures at the laundry facility. Remediation was designed and implemented by infection prevention and facility leadership teams.

RESULTS

Prior to remediation, 20% of HCLs were culture-positive for Mucorales upon hospital arrival. Laundry facility layout and processes were consistent with industry standards. Significant step-ups in Mucorales and mould culture-positivity of HCLs were detected at the post-dryer step (0% to 12% (p=0.04) and 5% to 29% (p=0.01), respectively). Further increases to 17% and 40% culture-positivity, respectively, were noted during pre-transport holding. Site inspection revealed heavy Mucorales-positive lint accumulation in rooftop air intake and exhaust vents that cooled driers; intake and exhaust vents that were facing each other; rooftop and plant-wide lint accumulation, including in the pre-transport clean room; uncovered carts with freshly-laundered HCLs. Following environmental remediation, quality assurance measures and education directed toward these sources, Mucorales culture-positivity of newly-delivered HCLs was reduced to 0.3% (p=0.0001); area of lint-contaminated rooftop decreased from 918 m 2 to 0 m 2 on satellite images.

CONCLUSIONS

Targeted laundry facility interventions guided by site inspections and step-wise culturing significantly reduced Mucorales-contaminated HCLs delivered to our hospital. Collaboration between infection prevention and laundry facility teams was crucial to successful remediation.

Patient notification about suspected hospital-associated outbreaks of invasive mold infections: Considerations for public health and hospital personnel

A common type of fungal disease investigation involves hospital-associated clusters of invasive mold infections (IMIs), which typically occur among immunocompromised patients. Responding to IMI clusters can be challenging for public health and hospital personnel for several reasons such as difficulty of confirming the existence of an outbreak, difficulty of determining source. Although many resources exist to guide patient notification about healthcare incidents (eg, bloodborne exposures, disease outbreaks), IMI clusters involve special considerations related to the complex diseases, uncertain exposures, and differential benefits and risks of notification. Early, nuanced communication about hospital-associated IMI clusters is almost always the best course of action to help reduce risks to patients' health and foster trust between patients and hospitals.

COVID-19 associated mucormycosis (CAM) in India: a formidable challenge

Together with the ongoing serious COVID-19 second wave in India, a serious fungal infection, mucormycosis has been increasingly found in COVID-19-recovered patients. Colloquially known as 'black fungus', mucormycosis commonly causes necrosis in the head and neck including the nose, paranasal sinuses, orbits, and facial bones, with possible intracranial spread. The disease causes high morbidity and mortality given that it progresses rapidly and diagnosis is often delayed. Given the sheer magnitude of the outbreak, the Indian Health Ministry has advised all states to declare mucormycosis an epidemic. Typically, the disease has been found to be linked to COVID-19 infections caused by the B.1.617.2 (Delta) variant, which has spread rapidly throughout the country. This variant has already become a cause for global concern, having spread to at least 40 countries, including the USA and UK. We present the findings of a study conducted on COVID-19 associated mucormycosis (CAM) patients, and discuss the associated risk factors to raise awareness for OMFS colleagues.

Superficial mycoses, a matter of concern: Global and Indian scenario-an updated analysis

Superficial mycoses of skin, nails and hair are among the common fungal infections. They are caused by dermatophytes, non-dermatophyte moulds, yeasts and yeast-like fungi. Such fungal infections are widespread all over the world and are predominant in tropical as well as subtropical regions. Environmental factors, such as warm, humid and pitiable hygienic conditions, are conducive for their growth and proliferation. Although it does not cause mortality, it is known to be associated with excessive morbidity which may be psychological or physical. This affects the quality of life of the infected individuals which leads to a negative impact on their occupational, emotional and social status. Such infections are increasing on a global scale and, therefore, are of serious concern worldwide. This review article covers the global and Indian scenario of superficial mycoses taking into account the historical background, aetiological agents, prevalence, cultural and environmental factors, risk factors, pathogenesis and hygienic practices for the prevention of superficial mycoses.

Genetic diversity of clinical and environmental Mucorales isolates obtained from an investigation of mucormycosis cases among solid organ transplant recipients

Mucormycoses are invasive infections by Rhizopus species and other Mucorales. Over 10 months, four solid organ transplant (SOT) recipients at our centre developed mucormycosis due to Rhizopus microsporus (n=2), R. arrhizus (n=1) or Lichtheimia corymbifera (n=1), at a median 31.5 days (range: 13-34) post-admission. We performed whole genome sequencing (WGS) on 72 Mucorales isolates (45 R. arrhizus, 19 R. delemar, six R. microsporus, two Lichtheimia species) from these patients, from five patients with community-acquired mucormycosis, and from hospital and regional environments. Isolates were compared by core protein phylogeny and global genomic features, including genome size, guanine-cytosine percentages, shared protein families and paralogue expansions. Patient isolates fell into six core phylogenetic lineages (clades). Phylogenetic and genomic similarities of R. microsporus isolates recovered 7 months apart from two SOT recipients in adjoining hospitals suggested a potential common source exposure. However, isolates from other patients and environmental sites had unique genomes. Many isolates that were indistinguishable by core phylogeny were distinct by one or more global genomic comparisons. Certain clades were recovered throughout the study period, whereas others were found at particular time points. In conclusion, mucormycosis cases could not be genetically linked to a definitive environmental source. Comprehensive genomic analyses eliminated false associations between Mucorales isolates that would have been assigned using core phylogenetic or less extensive genomic comparisons. The genomic diversity of Mucorales mandates that multiple isolates from individual patients and environmental sites undergo WGS during epidemiological investigations. However, exhaustive surveillance of fungal populations in a hospital and surrounding community is probably infeasible.

Epidemiology and Diagnosis of Mucormycosis: An Update

Mucormycosis is an angioinvasive fungal infection, due to fungi of the order Mucorales. Its incidence cannot be measured exactly, since there are few population-based studies, but multiple studies have shown that it is increasing. The prevalence of mucormycosis in India is about 80 times the prevalence in developed countries, being approximately 0.14 cases per 1000 population. Diabetes mellitus is the main underlying disease globally, especially in low and middle-income countries. In developed countries the most common underlying diseases are hematological malignancies and transplantation. Τhe epidemiology of mucormycosis is evolving as new immunomodulating agents are used in the treatment of cancer and autoimmune diseases, and as the modern diagnostic tools lead to the identification of previously uncommon genera/species such as Apophysomyces or Saksenaea complex. In addition, new risk factors are reported from Asia, including post-pulmonary tuberculosis and chronic kidney disease. New emerging species include Rhizopus homothallicus, Thamnostylum lucknowense, Mucor irregularis and Saksenaea erythrospora. Diagnosis of mucormycosis remains challenging. Clinical approach to diagnosis has a low sensitivity and specificity, it helps however in raising suspicion and prompting the initiation of laboratory testing. Histopathology, direct examination and culture remain essential tools, although the molecular methods are improving. The internal transcribed spacer (ITS) region is the most widely sequenced DNA region for fungi and it is recommended as a first-line method for species identification of Mucorales. New molecular platforms are being investigated and new fungal genetic targets are being explored. Molecular-based methods have gained acceptance for confirmation of the infection when applied on tissues. Methods on the detection of Mucorales DNA in blood have shown promising results for earlier and rapid diagnosis and could be used as screening tests in high-risk patients, but have to be validated in clinical studies. More, much needed, rapid methods that do not require invasive procedures, such as serology-based point-of-care, or metabolomics-based breath tests, are being developed and hopefully will be evaluated in the near future.

The role of textiles as fomites in the healthcare environment: a review of the infection control risk

BACKGROUND

Infectious diseases are a significant threat in both healthcare and community settings. Healthcare associated infections (HCAIs) in particular are a leading cause of complications during hospitalisation. Contamination of the healthcare environment is recognised as a source of infectious disease yet the significance of porous surfaces including healthcare textiles as fomites is not well understood. It is currently assumed there is little infection risk from textiles due to a lack of direct epidemiological evidence. Decontamination of healthcare textiles is achieved with heat and/or detergents by commercial or in-house laundering with the exception of healthcare worker uniforms which are laundered domestically in some countries. The emergence of the COVID-19 pandemic has increased the need for rigorous infection control including effective decontamination of potential fomites in the healthcare environment. This article aims to review the evidence for the role of textiles in the transmission of infection, outline current procedures for laundering healthcare textiles and review studies evaluating the decontamination efficacy of domestic and industrial laundering.

METHODOLOGY

Pubmed, Google Scholar and Web of Science were searched for publications pertaining to the survival and transmission of microorganisms on textiles with a particular focus on the healthcare environment.

RESULTS

A number of studies indicate that microorganisms survive on textiles for extended periods of time and can transfer on to skin and other surfaces suggesting it is biologically plausible that HCAIs and other infectious diseases can be transmitted directly through contact with contaminated textiles. Accordingly, there are a number of case studies that link small outbreaks with inadequate laundering or infection control processes surrounding healthcare laundry. Studies have also demonstrated the survival of potential pathogens during laundering of healthcare textiles, which may increase the risk of infection supporting the data published on specific outbreak case studies.

CONCLUSIONS

There are no large-scale epidemiological studies demonstrating a direct link between HCAIs and contaminated textiles yet evidence of outbreaks from published case studies should not be disregarded. Adequate microbial decontamination of linen and infection control procedures during laundering are required to minimise the risk of infection from healthcare textiles. Domestic laundering of healthcare worker uniforms is a particular concern due to the lack of control and monitoring of decontamination, offering a route for potential pathogens to enter the clinical environment. Industrial laundering of healthcare worker uniforms provides greater assurances of adequate decontamination compared to domestic laundering, due to the ability to monitor laundering parameters; this is of particular importance during the COVID-19 pandemic to minimise any risk of SARS-CoV-2 transmission.

Revisiting the "leading edge" of hospital privacy curtains in the medical intensive care unit

BACKGROUND

Privacy curtains within medical intensive care unit (MICU) rooms are a potential contributor to health care associated infections. The "leading edge" of a hospital curtain, estimated to be the edge most frequently touched, likely plays a role in health care associated infections at hospitals. The aims of this study were to (1) compare the bacterial load of the edge vs the middle of curtains in the MICU, and (2) determine the identity and distribution of relevant pathogens colonizing them.

METHODS

The edge and middle sections of 8 curtains in MICU rooms (4 contact precaution and 4 noncontact precaution) were sampled for culture on patient and staff sides. Bacterial loads of edges and middles were compared. Select isolates were further analyzed for species identification.

RESULTS

There was a statistically significant difference for the contact (t = 2.10, P = .047) and noncontact (t = 2.62, P = .016) rooms, with the edges having a significantly higher median than the middles. Pathogens such as methicillin-resistant Staphylococcus aureus, Enterococcus, Klebsiella, and Acinetobacter were found on the curtains, though at lower rates than in previous studies. Opportunistic fungi were also found on all curtains.

CONCLUSIONS

Results of this study confirm that hospital curtains, most notably the edge but also the middle, are contaminated with pathogens, and that these areas are frequently touched by health care workers in between hand hygiene.

Control of an outbreak of post-transplant cutaneous mucormycosis by removing the vehicle: An intervention study of contiguous cohorts

BACKGROUND

An outbreak of post-kidney transplant cutaneous mucormycosis (PK-CM), a severe and even fatal complication in immunocompromised patients, occurred in our institution. The objective of this study was to compare the usual fixation of sterile wound dressings with non-sterile elastic bandages and fixation with sterile bandages processed at our centralized sterile services department with regard to PK-CM prevention.

METHODS

We conducted a before-and-after trial in a private tertiary care hospital. The pre-intervention cohort (n = 16) included all patients who had undergone kidney transplant (KT) during the outbreak (June 2010-April 2011), and the post-intervention cohort (n = 49) included all patients who had undergone KT between May 2011 and October 2013. From May 2011, only bandages sterilized by the centralized sterile services department were used to fix wound dressings of KT patients.

RESULTS

Differences in age (50.2 years vs 51.3 years), sex (43.8% male vs 59.2% female), weight (63.3 kg vs 69.7 kg), hemodialysis vintage (55.6 months vs 47.8 months), and other risk factors were not observed between the pre- and post-intervention cohorts, respectively. PK-CM incidence dropped from 25% in the pre-intervention cohort (4/16) to 0% in the post-intervention cohort (0/49). Relative risk was 0 (P = .003).

CONCLUSIONS

With regard to KT patients and sterile wound dressing fixation with non-sterile bandages versus the use of autoclaved bandages, fixation with autoclaved bandages proved to be effective for cutaneous mucormycosis outbreak control and prevention in our institution.

How Clean Is the Linen at My Hospital? The Mucorales on Unclean Linen Discovery Study of Large United States Transplant and Cancer Centers

Mucormycosis outbreaks have been linked to contaminated linen. We performed fungal cultures on freshly-laundered linens at 15 transplant and cancer hospitals. At 33% of hospitals, the linens were visibly unclean. At 20%, Mucorales were recovered from >10% of linens. Studies are needed to understand the clinical significance of our findings.

Diagnostic Mycology: Xtreme Challenges

Developing any diagnostic assay that receives United States Food and Drug Administration (FDA) approval can be a slow and difficult process. FDA-approved assays for fungal diagnosis are generally few in number and are focused mainly on diagnosing candidiasis, which is caused by several species of Candida, in addition to a limited number of systemic mycotic agents. While all microbial diagnostic assays face challenges before they are FDA approved and reach the market, there are a number of challenges to fungal diagnostic assay development that have been difficult hurdles to overcome. These hurdles include template preparation, fungal morphology, how many fungi should be identified in a single assay (scope), taxonomy and nomenclature, discriminating colonizers from invasive infection, combining identification with antifungal susceptibility, and navigating the administrative hurdles required to integrate an assay into a clinical laboratory. Some of these challenges are easier to overcome than others, but all seem to be particularly difficult for fungal diagnostic assays.

Biotic Environments Supporting the Persistence of Clinically Relevant Mucormycetes

Clinically relevant members of the Mucorales group can grow and are found in diverse ecological spaces such as soil, dust, water, decomposing vegetation, on and in food, and in hospital environments but are poorly represented in mycobiome studies of outdoor and indoor air. Occasionally, Mucorales are found in water-damaged buildings. This mini review examines a number of specialised biotic environments, including those revealed by natural disasters and theatres of war, that support the growth and persistence of these fungi. However, we are no further forward in understanding exposure pathways or the chronicity of exposure that results in the spectrum of clinical presentations of mucormycosis.

Outbreaks of Mucorales and the Species Involved

The order Mucorales is an ancient group of fungi classified in the subphylum Mucoromycotina. Mucorales are mainly fast-growing saprotrophs that belong to the first colonizers of diverse organic materials and represent a permanent part of the human environment. Several species are able to cause human infections (mucormycoses) predominantly in patients with impaired immune system, diabetes, or deep trauma. In this review, we compiled 32 reports on community- and hospital-acquired outbreaks caused by Mucorales. The most common source of mucoralean outbreaks was contaminated medical devices that are responsible for 40.7% of the outbreaks followed by contaminated air (31.3%), traumatic inoculation of soil or foreign bodies (9.4%), and the contact (6.2%) or the ingestion (6.2%) of contaminated plant material. The most prevalent species were Rhizopus arrhizus and R. microsporus causing 57% of the outbreaks. The genus Rhizomucor was dominating in outbreaks related to contaminated air while outbreaks of Lichtheimia species and Mucor circinelloides were transmitted by direct contact. Outbreaks with the involvement of several species are reported. Subtyping of strains revealed clonality in two outbreaks and no close relation in two other outbreaks. Based on the existing data, outbreaks of Mucorales can be caused by heterogeneous sources consisting of different strains or different species. Person-to-person transmission cannot be excluded because Mucorales can sporulate on wounds. For a better understanding and prevention of outbreaks, we need to increase our knowledge on the physiology, ecology, and population structure of outbreak causing species and more subtyping data.

Drug-Resistant Epimutants Exhibit Organ-Specific Stability and Induction during Murine Infections Caused by the Human Fungal Pathogen Mucor circinelloides

The emerging fungal pathogen Mucor circinelloides causes a severe infection, mucormycosis, which leads to considerable morbidity and mortality. Treatment of Mucor infection is challenging because Mucor is inherently resistant to nearly all clinical antifungal agents. An RNAi-dependent and reversible mechanism of antifungal resistance, epimutation, was recently reported for Mucor. Epimutation has not been studied in vivo, and it was unclear whether it would contribute to antifungal resistance observed clinically. We demonstrate that epimutation can both be induced and reverted after in vivo passage through a mouse; rates of both induction and reversion are higher after brain infection than after infection of other organs (liver, spleen, kidneys, or lungs). Elucidating the roles played by epimutation in drug resistance and infection will improve our understanding of Mucor and other fungal pathogens and may have implications for antifungal treatment.

The environmentally ubiquitous fungus Mucor circinelloides is a primary cause of the emerging disease mucormycosis. Mucor infection is notable for causing high morbidity and mortality, especially in immunosuppressed patients, while being inherently resistant to the majority of clinically available antifungal drugs. A new, RNA interference (RNAi)-dependent, and reversible epigenetic mechanism of antifungal resistance—epimutation—was recently discovered in M. circinelloides. However, the effects of epimutation in a host-pathogen setting were unknown. We employed a systemic, intravenous murine model of Mucor infection to elucidate the potential impact of epimutation in vivo. Infection with an epimutant strain resistant to the antifungal agents FK506 and rapamycin revealed that the epimutant-induced drug resistance was stable in vivo in a variety of different organs and tissues. Reversion of the epimutant-induced drug resistance was observed to be more rapid in isolates from the brain than in isolates recovered from the liver, spleen, kidney, or lungs. Importantly, infection with a wild-type strain of Mucor led to increased rates of epimutation after strains were recovered from organs and exposed to FK506 stress in vitro. Once again, this effect was more pronounced in strains recovered from the brain than from other organs. In summary, we report the rapid induction and reversion of RNAi-dependent drug resistance after in vivo passage through a murine model, with pronounced impact in strains recovered from brain. Defining the role played by epimutation in drug resistance and infection advances our understanding of Mucor and other fungal pathogens and may have implications for antifungal therapy.

Mucormycosis diagnosed during induction chemotherapy in five pediatric patients with acute lymphoblastic leukemia

Mucormycosis in pediatric oncology patients is a rare invasive fungal infection associated with significant morbidity and mortality. We describe five patients diagnosed with mucormycosis during induction chemotherapy for acute lymphoblastic leukemia at our institution. All of the patients in our series survived, some in spite of having disseminated disease. Most of the patients' chemotherapy was modified with the aim of controlling their leukemia while minimizing immunosuppression until their fungal infection was under control. Although mucormycosis is frequently fatal, rapid diagnosis and a multidisciplinary approach can lead to excellent outcomes, even in patients undergoing intensive chemotherapy.

A Guide to Investigating Suspected Outbreaks of Mucormycosis in Healthcare

This report serves as a guide for investigating mucormycosis infections in healthcare. We describe lessons learned from previous outbreaks and offer methods and tools that can aid in these investigations. We also offer suggestions for conducting environmental assessments, implementing infection control measures, and initiating surveillance to ensure that interventions were effective. While not all investigations of mucormycosis infections will identify a single source, all can potentially lead to improvements in infection control.

How clean is "hygienically clean": Quantitative microbial levels from samples of clean health care textiles across the United States

BACKGROUND

In the United States, the laundry industry has not reliably measured microbial levels on hygienically clean textiles. The aim of this study was to quantitatively measure the microbial levels found on a sample of hygienically clean textiles.

METHODS

Forty-eight health care textile samples were collected from hygienically clean linen scheduled to be used on 3 different patient care units. Samples were taken at 2 separate points in time representing laundry facility processing practices and hospital linen management practices. United States Pharmacopeia 61 testing was completed using a pour plate culturing method, producing a total aerobic microbial count and a total yeast and mold count.

RESULTS

Of the samples, only 27% had a total aerobic microbial count below the expected 100 colony-forming unit level (range, 9-40,000) versus 81% (range, 9-1,000) for total yeast and mold count. Median microbial counts for the 2 separate time points across the 3 different patient care units were also higher than expected.

CONCLUSIONS

As far as we know, this study is a first step by the laundry industry to understand what quantitative microbial levels are currently found on hygienically clean health care textiles. These types of data can assist the industry in establishing appropriate outcome targets for process improvement initiatives.

Pathogenicity patterns of mucormycosis: epidemiology, interaction with immune cells and virulence factors

Fungi of the basal lineage order Mucorales are able to cause infections in animals and humans. Mucormycosis is a well-known, life-threatening disease especially in patients with a compromised immune system. The rate of mortality and morbidity caused by mucormycosis has increased rapidly during the last decades, especially in developing countries. The systematic, phylogenetic, and epidemiological distributions of mucoralean fungi are addressed in relation to infection in immunocompromised patients. The review highlights the current achievements in (i) diagnostics and management of mucormycosis, (ii) the study of the interaction of Mucorales with cells of the innate immune system, (iii) the assessment of the virulence of Mucorales in vertebrate and invertebrate infection models, and (iv) the determination of virulence factors that are key players in the infection process, for example, high-affinity iron permease (FTR1), spore coat protein (CotH), alkaline Rhizopus protease enzyme (ARP), ADP-ribosylation factor (ARF), dihydrolipoyl dehydrogenase, calcineurin (CaN), serine and aspartate proteases (SAPs). The present mini-review attempts to increase the awareness of these difficult-to-manage fungal infections and to encourage research in the detection of ligands and receptors as potential diagnostic parameters and drug targets.

Global Epidemiology of Mucormycosis

Mucormycosis is an angio-invasive fungal infection, associated with high morbidity and mortality. A change in the epidemiology of mucormycosis has been observed in recent years with the rise in incidence, new causative agents and susceptible population. The rise has been perceived globally, but it is very high in the Asian continent. Though diabetes mellitus overshadow all other risk factors in Asia, post-tuberculosis and chronic renal failure have emerged as new risk groups. The rhino-cerebral form of mucormycosis is most commonly seen in patients with diabetes mellitus, whereas, pulmonary mucormycosis in patients with haematological malignancy and transplant recipients. In immunocompetent hosts, cutaneous mucormycosis is commonly seen following trauma. The intriguing clinical entity, isolated renal mucormycosis in immunocompetent patients is only reported from China and India. A new clinical entity, indolent mucormycosis in nasal sinuses, is recently recognized. The causative agents of mucormycosis vary across different geographic locations. Though Rhizopusarrhizus is the most common agent isolated worldwide, Apophysomycesvariabilis is predominant in Asia and Lichtheimia species in Europe. The new causative agents, Rhizopus homothallicus, Mucor irregularis, and Thamnostylum lucknowense are reported from Asia. In conclusion, with the change in epidemiology of mucormycosis country-wise studies are warranted to estimate disease burden in different risk groups, analyse the clinical disease pattern and identify the new etiological agents.

Disease Entities in Mucormycosis

Mucormycosis is an emerging life-threatening fungal infection caused by Mucorales. This infection occurs mainly in immunocompromised patients, especially with hematological malignancy, transplantation, or diabetes mellitus. Rhino-orbito-cerebral and pulmonary mucormycosis are the predominant forms. Interestingly, location is associated with the underlying disease as pulmonary mucormycosis is more frequent in hematological malignancy patients whereas rhino-orbito-cerebral mucormycosis is associated with diabetes. Cutaneous mucormycosis results from direct inoculation, mainly after trauma or surgery. Gastro-intestinal mucormycosis occurs after ingestion of contaminated food or with contaminated device and involves the stomach or colon. Disseminated disease is the most severe form and is associated with profound immunosuppression. Uncommon presentations with endocarditis, osteoarticluar or isolated cerebral infections are also described. Finally, health-care associated mucormycosis is a matter of concern in premature newborns and burn units. Clinical symptoms and CT scan findings are not specific, only the early reversed halo sign is associated with pulmonary mucormycosis. Circulating Mucorales DNA detection is a recent promising diagnostic tool that may lead to improving the diagnosis and prompting therapeutic initiation that should include antifungal treatment, correction of the underlying disease and surgery when feasible.

CRISPR-Cas9 induces point mutation in the mucormycosis fungus Rhizopus delemar

Rhizopus delemar causes devastating mucormycosis in immunodeficient individuals. Despite its medical importance, R. delemar remains understudied largely due to the lack of available genetic markers, the presence of multiple gene copies due to genome duplication, and mitotically unstable transformants resulting from conventional and limited genetic approaches. The clustered regularly interspaced short palindromic repeat (CRISPR)-associated nuclease 9 (Cas9) system induces efficient homologous and non-homologous break points and generates individual and multiple mutant alleles without requiring selective marker genes in a wide variety of organisms including fungi. Here, we have successfully adapted this technology for inducing gene-specific single nucleotide (nt) deletions in two clinical strains of R. delemar: FGSC-9543 and CDC-8219. For comparative reasons, we first screened for spontaneous uracil auxotrophic mutants resistant to 5-fluoroorotic acid (5-FOA) and obtained one substitution (f1) mutationin the FGSC-9543 strain and one deletion (f2) mutation in the CDC-8219 strain. The f2 mutant was then successfully complemented with a pyrF-dpl200 marker gene. We then introduced a vector pmCas9:tRNA-gRNA that expresses both Cas9 endonuclease and pyrF-specific gRNA into FGSC-9543 and CDC-8219 strains and obtained 34 and 42 5-FOA resistant isolates, respectively. Candidate transformants were successively transferred eight times by propagating hyphal tips prior to genotype characterization. Sequencing of the amplified pyrF allele in all transformants tested revealed a single nucleotide (nt) deletion at the 4th nucleotide before the protospacer adjacent motif (PAM) sequence, which is consistent with CRISPR-Cas9 induced gene mutation through non-homologous end joining (NHEJ). Our study provides a new research tool for investigating molecular pathogenesis mechanisms of R. delemar while also highlighting the utilization of CRISPR-Cas9 technology for generating specific mutants of Mucorales fungi.

Generation of A Mucor circinelloides Reporter Strain-A Promising New Tool to Study Antifungal Drug Efficacy and Mucormycosis

Invasive fungal infections caused by Mucorales (mucormycosis) have increased worldwide. These life-threatening infections affect mainly, but not exclusively, immunocompromised patients, and are characterized by rapid progression, severe tissue damage and an unacceptably high rate of mortality. Still, little is known about this disease and its successful therapy. New tools to understand mucormycosis and a screening method for novel antimycotics are required. Bioluminescent imaging is a powerful tool for in vitro and in vivo approaches. Hence, the objective of this work was to generate and functionally analyze bioluminescent reporter strains of Mucor circinelloides, one mucormycosis-causing pathogen. Reporter strains were constructed by targeted integration of the firefly luciferase gene under control of the M. circinelloides promoter Pzrt1. The luciferase gene was sufficiently expressed, and light emission was detected under several conditions. Phenotypic characteristics, virulence potential and antifungal susceptibility were indifferent to the wild-type strains. Light intensity was dependent on growth conditions and biomass, being suitable to determine antifungal efficacy in vitro. This work describes for the first time the generation of reporter strains in a basal fungus that will allow real-time, non-invasive infection monitoring in insect and murine models, and the testing of antifungal efficacy by means other than survival.

Gangrenous Necrotizing Cutaneous Mucormycosis in an Immunocompetent Neonate: A Case Report from Oman

We describe a case of progressive cutaneous mucormycosis, which caused gangrenous necrotizing fasciitis, in an immunocompetent neonate from Oman. Extensive wound contamination and a favorable environment for the growth of Mucorales were the predisposing factors. Early aggressive management including frequent wound debridement, targeted pharmacotherapy with liposomal amphotericin B and supportive care is pivotal for improved outcomes.